<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <link rel="stylesheet" href="./flex.css">
  <style>
    html {
      padding: 60px;
    }
    body {
      width: 100%;
      height: 100%;
      padding: 0;
      margin: 0;
      border: 1px solid #3232f6;
    }
    * {
      box-sizing: border-box;
    }
    .row,
    .row-reverse {
      margin-bottom: 20px;
      background: rgba(0, 0, 0, 0.1);
    }
    .inner {
      background: rgba(0, 0, 0, 0.1);
    }
    [class*="col-"] {
      height: 20px;
      border: 1px solid red;
    }
  </style>
</head>
<body>
<div class="flex">
  <div class="same col-1"><div class="inner">xx</div></div>
  <div class="same col-1"><div class="inner">xx</div></div>
  <div class="same col-1"><div class="inner">xx</div></div>
</div>
<div class="flex">
  <div class="same col-2"><div class="inner">xxx-xx</div></div>
  <div class="same col-2 offset-1"><div class="inner">xxx-xx</div></div>
  <div class="same col-2 offset-1"><div class="inner">xxx-xx</div></div>
</div>
<div class="flex-reverse">
  <div class="same col-2"><div class="inner">xxx-xx</div></div>
  <div class="same col-2 offset-1"><div class="inner">xxx-xx</div></div>
  <div class="same col-2 offset-1"><div class="inner">xxx-xx</div></div>
</div>
<div class="flex flex-gutter-large">
  <div class="same col-2"><div class="inner">xxx-xx</div></div>
  <div class="same col-2 offset-3"><div class="inner">xxx-xx</div></div>
  <div class="same col-2"><div class="inner">xxx-xx</div></div>
</div>
<div class="flex flex-gutter-24">
  <div class="same col-12"><div class="inner">xxx-xx</div></div>
  <div class="same col-12"><div class="inner">xxx-xx</div></div>
  <div class="same col-12 offset-12"><div class="inner">xxx-xx</div></div>
</div>
</body>
</html>